1. Field of the Invention
The invention relates generally to electrostatic atomizers and more particularly to an electrostatic atomizer that employs electrostatic atomization of water to generate mist of charged fine particles in the order of nanometer in size.
2. Description of the Related Art
Such sort of electrostatic atomizer is seen in, for example, the patent document of Japanese Patent Number 3260150 (European Patent Publication Number 0 486 198 A1 or U.S. Pat. No. 5,337,963). A prior art device described in the document comprises a cartridge for storage of liquid suitable for electrostatic spraying, and a high voltage means for applying electrostatic potential to the liquid. The cartridge includes a capillary structure that extends into the interior of the cartridge so as to feed liquid by capillary action from the cartridge to a spraying outlet at a tip of the capillary structure. The cartridge also includes a means for providing an electrically conductive path to allow the application of an electrostatic charge to the liquid. When the high voltage means applies the potential to the liquid at the mouth of the spraying outlet, a potential gradient is developed between innermost and outermost peripheral surfaces of the mouth, and draws the liquid across an end face of the spraying outlet towards the outermost peripheral surface. Thereby, the liquid is projected electrostatically as an array of ligaments which form a halo around the mouth. In another configuration, the device is further provided with an electrode connected to a low potential such as earth.
However, because the high voltage means applies electrostatic potential within the range from 10 kV to 25 kV to an electrical contact in the cartridge, there is an issue that (stress) migration occurs at the electrical contact.